1. Field of the Invention
The present invention relates to an electric propulsion system control apparatus having an electric drive motor that drives a propulsion propeller to rotate, current detecting means for detecting a current of the electric drive motor, rotation speed detecting means for detecting a rotation speed of the electric drive motor, and drive control means for controlling the electric drive motor, and more particularly to an electric propulsion system control apparatus suitable for drive-controlling a propulsion propeller of an aircraft.
2. Description of the Related Art
To fly an aircraft safely and efficiently, it is important to monitor an airspeed and an atmospheric density during flight.
In an aircraft, the airspeed is typically detected by detecting a dynamic pressure that is proportional to a square of the airspeed using a pressure gauge connected by a pipe to a Pitot tube.
In this method, a maximum delay of approximately several seconds may occur before dynamic pressure variation occurring at a tip end of the Pitot tube propagates through the pipe so as to reach the pressure gauge and be detected as airspeed variation, and therefore this method is problematic when applied to a case in which the airspeed varies over time.
To maintain efficiency in a propulsion system of the aircraft, and thereby stabilize an attitude and an altitude of an airframe, operating conditions of the propulsion system such as a rotation speed and a pitch angle of a propeller must be adjusted in accordance with the airspeed.
However, when airspeed detecting means employing the aforementioned Pitot tube is used in cases where the airspeed varies over time, such as during a takeoff run or in gusty conditions, airspeed detection and operating condition adjustment cannot be performed in a timely fashion relative to the airspeed variation, leading to a reduction in efficiency, and as a result, problems such as an increased takeoff run length and a large loss of altitude may occur.
Highly responsive airspeed detecting means such as a hot wire anemometer also exists, but demerits pertaining to cost, weight, and so on are unavoidable when such means is installed in an aircraft.